This invention relates to an expanded board of sheet-like structure and a process for manufacturing the same, and particularly to a novel food product in the form of a thin wafer-like sheet expanded in thickness and having a plurality of elongated chambers rectangular in cross section and the process for manufacturing the same.
In the prior art, many types of board or sheet-like structures were used in many fields from the view point of shock absorbing characteristics, improved solubility, increased surface area, decreased weight, etc. However, in the prior art, expanded board or sheet like structure can be obtained only with many difficulties, for example corrugated board or sheet can be obtained by only two processes.
One such process includes an extrusion through a nozzle means. The other is a conventional corrugated cardboard manufacturing process wherein corrugated board is produced by coating both sides, that is, the tops of the mountain parts of the corrugated medium moulded into the shape of wave, with starch solution, putting on the both sides, surface and back side liners, and further passing it onto a hot plate heated at 160.degree. C - 180.degree. C to make the starch solution pasty by heated liners, followed by drying.
However, the former process has the disadvantages of expensive machine costs and the difficulty of maintaining quality product control, particularly for the productionof a thin sheet. The latter process also has similar disadvantages accompanied by large sized machine installation and the difficulty in obtaining a small sized product. A small sized product has been needed for many years and for many fields, particularly for food industries.
Accordingly, it is the object of the present invention to provide a novel process for the production of a novel expanded board or sheet-like structure improved in strength and appearance, and without using conventional machinery.